1. Field of the Invention
The present invention relates to a method for a network of a wireless communication system, and more particularly, to a method of handling short message service (SMS) re-delivery for a network of a wireless communication system.
2. Description of the Prior Art
A long-term evolution (LTE) system supporting the 3GPP Rel-8 standard and/or the 3GPP Rel-9 standard are developed by the 3rd Generation Partnership Project (3GPP) as a successor of a universal mobile telecommunications system (UMTS), for further enhancing performance of the UMTS to satisfy increasing needs of users. The LTE system includes a new radio interface and a new radio network architecture that provides a high data rate, low latency, packet optimization, and improved system capacity and coverage. In the LTE system, a radio access network known as an evolved universal terrestrial radio access network (E-UTRAN) includes multiple evolved Node-Bs (eNBs) for communicating with multiple user equipments (UEs), and communicating with a core network including a mobility management entity (MME), a serving gateway, etc., for Non-Access Stratum (NAS) control.
A LTE-advanced (LTE-A) system, as its name implies, is an evolution of the LTE system. The LTE-A system targets faster switching between power states, improves performance at the coverage edge of an eNB, and includes advanced techniques, such as carrier aggregation (CA), coordinated multipoint transmission/reception (CoMP), UL multiple-input multiple-output (MIMO), etc. For a UE and an eNB to communicate with each other in the LTE-A system, the UE and the eNB must support standards developed for the LTE-A system, such as the 3GPP Rel-10 standard or later versions.
The Mobile Subscriber Integrated Services Digital Network Number (MSISDN) together with International mobile Subscriber Identity (IMSI) are two important numbers used for identifying a mobile subscriber. The IMSI identifies the subscriber identity module (SIM) card, and the MSISDN is used for routing calls to the user. Simply put, the MSISDN is the telephone number to the SIM card in a mobile phone. Nowadays, the number of the mobile devices significantly increases and the MSISDN may run out due to the limited digits of the MSISDN. In other words, part of the communication devices may not have the corresponded MSISDN in the near feature. Thus, how to operate the wireless communication system having the communication devices without the MSISDN becomes an important topic to be discussed.
If a short message(SM) is failed to deliver due to temporary error, e.g., the UE is un-reachable or out of memory, the short message is stored in the short message service center (SMSC) for redelivery. The HSS/HLR sets the message waiting data (MWD) which is part of message waiting indication (MWI) to associate the UE and the SMSC storing the failed SM. The MWD contains the MSISDN or IMSI of the UE and a list of SMSC address.